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Supplemental Data

Table S5: Data from this study have been submitted to the European Genome-Phenome Archive (EGA) (www.ebi.ac.uk/ega/home) under the study accession number EGAS00001001159. This table provides the accession numbers for each dataset included in this study.

Supplementary Figures S1-S5. Supplementary Tables S1-S5. Figure S1. Comparison of SNV mutation signatures across histological and molecular subtypes. Figure S2. Treatment timelines and radiographic outcomes. Figure S3. Mutation signature stability metrics and comparisons to known signatures. Figure S4. Structural variant mutation sigantures. Figure S5. Comparison of mutation burden between aging-driven and non-aging-driven breast tumours. Table S1. Kruskal-Wallis tests. Table S2. HRDetect prediction test metrics. Table S3. Area under the curve of HRD signatures in platinum response prediction. Table S4. Logistic regression model odds ratios of clinical improvement on platinum. Table S5. Accession IDs of genome datasets submitted to the European Genome-Phenome Archive.

Supplemental Table 2

Supplemental Table 1

Purpose:Gene fusions are important oncogenic drivers and many are actionable. Whole-genome and transcriptome (WGS and RNA-seq, respectively) sequencing can discover novel clinically relevant fusions.Experimental Design:Using WGS and RNA-seq, we reviewed the prevalence of fusions in a cohort of 570 patients with cancer, and compared prevalence to that predicted with commercially available panels. Fusions were annotated using a consensus variant calling pipeline (MAVIS) and required that a contig of the breakpoint could be constructed and supported from ≥2 structural variant detection approaches.Results:In 570 patients with advanced cancer, MAVIS identified 81 recurrent fusions by WGS and 111 by RNA-seq, of which 18 fusions by WGS and 19 by RNA-seq were noted in at least 3 separate patients. The most common fusions were EML4-ALK in thoracic malignancies (9/69, 13%), and CMTM8-CMTM7 in colorectal cancer (4/73, 5.5%). Combined genomic and transcriptomic analysis identified novel fusion partners for clinically relevant genes, such as NTRK2 (novel partners: SHC3, DAPK1), and NTRK3 (novel partners: POLG, PIBF1).Conclusions:Utilizing WGS/RNA-seq facilitates identification of novel fusions in clinically relevant genes, and detected a greater proportion than commercially available panels are expected to find. A significant benefit of WGS and RNA-seq is the innate ability to retrospectively identify variants that becomes clinically relevant over time, without the need for additional testing, which is not possible with panel-based approaches.

Purpose: Recent studies have identified mutation signatures of homologous recombination deficiency (HRD) in over 20% of breast cancers, as well as pancreatic, ovarian, and gastric cancers. There is an urgent need to understand the clinical implications of HRD signatures. Whereas BRCA1/2 mutations confer sensitivity to platinum-based chemotherapies, it is not yet clear whether mutation signatures can independently predict platinum response.Experimental Design: In this observational study, we sequenced tumor whole genomes (100× depth) and matched normals (60×) of 93 advanced-stage breast cancers (33 platinum-treated). We computed a published metric called HRDetect, independently trained to predict BRCA1/2 status, and assessed its capacity to predict outcomes on platinum-based chemotherapies. Clinical endpoints were overall survival (OS), total duration on platinum-based therapy (TDT), and radiographic evidence of clinical improvement (CI).Results: HRDetect predicted BRCA1/2 status with an area under the curve (AUC) of 0.94 and optimal threshold of 0.7. Elevated HRDetect was also significantly associated with CI on platinum-based therapy (AUC = 0.89; P = 0.006) with the same optimal threshold, even after adjusting for BRCA1/2 mutation status and treatment timing. HRDetect scores over 0.7 were associated with a 3-month extended median TDT (P = 0.0003) and 1.3-year extended median OS (P = 0.04).Conclusions: Our findings not only independently validate HRDetect, but also provide the first evidence of its association with platinum response in advanced breast cancer. We demonstrate that HRD mutation signatures may offer clinically relevant information independently of BRCA1/2 mutation status and hope this work will guide the development of clinical trials. Clin Cancer Res; 23(24); 7521–30. ©2017 AACR.

Background Single‐arm trials are common in precision oncology. Owing to the lack of randomized counterfactual, resultant data are not amenable to comparative outcomes analyses. Difference‐in‐difference (DID) methods present an opportunity to generate causal estimates of time‐varying treatment outcomes. Using DID, our study estimates within‐cohort effects of genomics‐informed treatment versus standard care on clinical and cost outcomes. Methods We focus on adults with advanced cancers enrolled in the single‐arm BC Cancer Personalized OncoGenomics program between 2012 and 2017. All individuals had a minimum of 1‐year follow up. Logistic regression explored baseline differences across patients who received a genomics‐informed treatment versus a standard care treatment after genomic sequencing. DID estimated the incremental effects of genomics‐informed treatment on time to treatment discontinuation (TTD), time to next treatment (TTNT), and costs. TTD and TTNT correlate with improved response and survival. Results Our study cohort included 346 patients, of whom 140 (40%) received genomics‐informed treatment after sequencing and 206 (60%) received standard care treatment. No significant differences in baseline characteristics were detected across treatment groups. DID estimated that the incremental effect of genomics‐informed versus standard care treatment was 102 days (95% CI: 35, 167) on TTD, 91 days (95% CI: −9, 175) on TTNT, and CAD$91,098 (95% CI: $46,848, $176,598) on costs. Effects were most pronounced in gastrointestinal cancer patients. Conclusions Genomics‐informed treatment had a statistically significant effect on TTD compared to standard care treatment, but at increased treatment costs. Within‐cohort evidence generated through this single‐arm study informs the early‐stage comparative effectiveness of precision oncology., Difference‐in‐difference analysis is used to address confounding when analyzing real‐world data from a single‐arm precision oncology trial. Enrolled patients receiving genomics‐informed treatment are treated longer, suggesting improved efficacy, but at an increased cost compared to those receiving standard care.

This is the first report of a NACC2‐NTRK2 fusion in a histological glioblastoma. Oncogenomic analysis revealed this actionable fusion oncogene in a pediatric cerebellar glioblastoma, which would not have been identified through routine diagnostics, demonstrating the value of clinical genome profiling in cancer care.

Purpose:Gene fusions are important oncogenic drivers and many are actionable. Whole-genome and transcriptome (WGS and RNA-seq, respectively) sequencing can discover novel clinically relevant fusions.Experimental Design:Using WGS and RNA-seq, we reviewed the prevalence of fusions in a cohort of 570 patients with cancer, and compared prevalence to that predicted with commercially available panels. Fusions were annotated using a consensus variant calling pipeline (MAVIS) and required that a contig of the breakpoint could be constructed and supported from ≥2 structural variant detection approaches.Results:In 570 patients with advanced cancer, MAVIS identified 81 recurrent fusions by WGS and 111 by RNA-seq, of which 18 fusions by WGS and 19 by RNA-seq were noted in at least 3 separate patients. The most common fusions were EML4-ALK in thoracic malignancies (9/69, 13%), and CMTM8-CMTM7 in colorectal cancer (4/73, 5.5%). Combined genomic and transcriptomic analysis identified novel fusion partners for clinically relevant genes, such as NTRK2 (novel partners: SHC3, DAPK1), and NTRK3 (novel partners: POLG, PIBF1).Conclusions:Utilizing WGS/RNA-seq facilitates identification of novel fusions in clinically relevant genes, and detected a greater proportion than commercially available panels are expected to find. A significant benefit of WGS and RNA-seq is the innate ability to retrospectively identify variants that becomes clinically relevant over time, without the need for additional testing, which is not possible with panel-based approaches.

Purpose Structural variants (SVs) may be an underestimated cause of hereditary cancer syndromes given the current limitations of short-read next-generation sequencing. Here we investigated the utility of long-read sequencing in resolving germline SVs in cancer susceptibility genes detected through short-read genome sequencing. Methods Known or suspected deleterious germline SVs were identified using Illumina genome sequencing across a cohort of 669 advanced cancer patients with paired tumor genome and transcriptome sequencing. Candidate SVs were subsequently assessed by Oxford Nanopore long-read sequencing. Results Nanopore sequencing confirmed eight simple pathogenic or likely pathogenic SVs, resolving three additional variants whose impact could not be fully elucidated through short-read sequencing. A recurrent sequencing artifact on chromosome 16p13 and one complex rearrangement on chromosome 5q35 were subsequently classified as likely benign, obviating the need for further clinical assessment. Variant configuration was further resolved in one case with a complex pathogenic rearrangement affecting TSC2. Conclusion Our findings demonstrate that long-read sequencing can improve the validation, resolution, and classification of germline SVs. This has important implications for return of results, cascade carrier testing, cancer screening, and prophylactic interventions.

Next-generation sequencing of solid tumors has revealed variable signatures of immunogenicity across tumors, but underlying molecular characteristics driving such variation are not fully understood. Although expression of endogenous retrovirus (ERV)-containing transcripts can provide a source of tumor-specific neoantigen in some cancer models, associations between ERV levels and immunogenicity across different types of metastatic cancer are not well established. We performed bioinformatics analysis of genomic, transcriptomic, and clinical data across an integrated cohort of 199 patients with metastatic breast, colorectal, and pancreatic ductal adenocarcinoma tumors. Within each cancer type, we identified a subgroup of viral mimicry tumors in which increased ERV levels were coupled with transcriptional signatures of autonomous antiviral response and immunogenicity. In addition, viral mimicry colorectal and pancreatic tumors showed increased expression of DNA demethylation gene TET2. Taken together, these data demonstrate the existence of an ERV-associated viral mimicry phenotype across three distinct metastatic cancer types, while indicating links between ERV abundance, epigenetic dysregulation, and immunogenicity.

Advanced and metastatic tumors with complex treatment histories drive cancer mortality. Here we describe the POG570 cohort, a comprehensive whole-genome, transcriptome and clinical dataset, amenable for exploration of the impacts of therapies on genomic landscapes. Previous exposure to DNA-damaging chemotherapies and mutations affecting DNA repair genes, including POLQ and genes encoding Polζ, were associated with genome-wide, therapy-induced mutagenesis. Exposure to platinum therapies coincided with signatures SBS31 and DSB5 and, when combined with DNA synthesis inhibitors, signature SBS17b. Alterations in ESR1, EGFR, CTNNB1, FGFR1, VEGFA and DPYD were consistent with drug resistance and sensitivity. Recurrent noncoding events were found in regulatory region hotspots of genes including TERT, PLEKHS1, AP2A1 and ADGRG6. Mutation burden and immune signatures corresponded with overall survival and response to immunotherapy. Our data offer a rich resource for investigation of advanced cancers and interpretation of whole-genome and transcriptome sequencing in the context of a cancer clinic. Marra and colleagues describe POG570, a pan-cancer, whole-genome, transcriptome and clinical dataset stressing the molecular interactions in advanced and post-therapy cancer patients.

PURPOSE This study investigated therapeutic potential of integrated genome and transcriptome profiling of metastatic sarcoma, a rare but extremely heterogeneous group of aggressive mesenchymal malignancies with few systemic therapeutic options. METHODS Forty-three adult patients with advanced or metastatic non-GI stromal tumor sarcomas of various histology subtypes who were enrolled in the Personalized OncoGenomics program at BC Cancer were included in this study. Fresh tumor tissues along with blood samples underwent whole-genome and transcriptome sequencing. RESULTS The most frequent genomic alterations in this cohort are large-scale structural variation and somatic copy number variation. Outlier RNA expression as well as somatic copy number variations, structural variations, and small mutations together suggest the presence of one or more potential therapeutic targets in the majority of patients in our cohort. Point mutations or deletions in known targetable cancer genes are rare; for example, tuberous sclerosis complex 2 provides a rationale for targeting the mammalian target of rapamycin pathway, resulting in a few patients with exceptional clinical benefit from everolimus. In addition, we observed recurrent 17p11-12 amplifications, which seem to be a sarcoma-specific event. This may suggest that this region harbors an oncogene(s) that is significant for sarcoma tumorigenesis. Furthermore, some sarcoma tumors carrying a distinct mutational signature suggestive of homologous recombination deficiency seem to demonstrate sensitivity to double-strand DNA–damaging agents. CONCLUSION Integrated large-scale genomic analysis may provide insights into potential therapeutic targets as well as novel biologic features of metastatic sarcomas that could fuel future experimental and clinical research and help design biomarker-driven basket clinical trials for novel therapeutic strategies.

Purpose: Gene fusions involving neuregulin 1 (NRG1) have been noted in multiple cancer types and have potential therapeutic implications. Although varying results have been reported in other cancer types, the efficacy of the HER-family kinase inhibitor afatinib in the treatment of NRG1 fusion–positive pancreatic ductal adenocarcinoma is not fully understood. Experimental Design: Forty-seven patients with pancreatic ductal adenocarcinoma received comprehensive whole-genome and transcriptome sequencing and analysis. Two patients with gene fusions involving NRG1 received afatinib treatment, with response measured by pretreatment and posttreatment PET/CT imaging. Results: Three of 47 (6%) patients with advanced pancreatic ductal adenocarcinoma were identified as KRAS wild type by whole-genome sequencing. All KRAS wild-type tumors were positive for gene fusions involving the ERBB3 ligand NRG1. Two of 3 patients with NRG1 fusion–positive tumors were treated with afatinib and demonstrated a significant and rapid response while on therapy. Conclusions: This work adds to a growing body of evidence that NRG1 gene fusions are recurrent, therapeutically actionable genomic events in pancreatic cancers. Based on the clinical outcomes described here, patients with KRAS wild-type tumors harboring NRG1 gene fusions may benefit from treatment with afatinib. See related commentary by Aguirre, p. 4589

Cancers routinely exhibit chromosomal instability, resulting in the accumulation of changes in the abundance of genomic material, known as copy number variants (CNVs). Unfortunately, the detection of these variants in cancer genomes is difficult. We developed Ploidetect, a software package that effectively identifies CNVs within whole-genome sequenced tumors. Ploidetect was more sensitive to CNVs in cancer related genes within advanced, pre-treated metastatic cancers than other tools, while also segmenting the most contiguously. Chromosomal instability, as measured by segment contiguity, was associated with several biological and clinical variables, including tumor mutation burden, tumor type, duration of therapy and immune microenvironment, highlighting the relevance of measuring CNV across the cancer genome. Investigation of gene mutations in samples revealed and the mutation status of several genes including ROCK2 and AC074391.1. Leveraging our heightened ability to detect CNVs, we identified 282 genes which were recurrently homozygously deleted in metastatic tumors. Further analysis of one recurrently deleted gene, MACROD2, identified a putative fragile tumor suppressor locus associated with response to chromosomal instability and chemotherapeutic agents. Our results outline the multifaceted impacts of CNVs in cancer by providing evidence of their involvement in tumorigenic behaviors and their utility as biomarkers for biological processes. We propose that increasingly accurate determination of CNVs is critical for their productive study in cancer, and our work demonstrates advances made possible by progress in this regard.

Manual interpretation of variants remains rate limiting in precision oncology. The increasing scale and complexity of molecular data generated from comprehensive sequencing of cancer samples requires advanced interpretative platforms as precision oncology expands beyond individual patients to entire populations. To address this unmet need, we created the Platform for Oncogenomic Reporting and Interpretation (PORI), comprising an analytic framework created to facilitate the interpretation and reporting of somatic variants in cancer. PORI is unique in its integration of reporting and graph knowledge base tools combined with support for manual curation at the reporting stage. PORI represents one of the first open-source platform alternatives to commercial reporting solutions suitable for comprehensive genomic data sets in precision oncology. We demonstrate the utility of PORI by matching 9,961 TCGA tumours to the graph knowledge base, revealing that 88.2% have at least one potentially targetable alteration, and making available reports describing select individual samples.

Inherited genetic variation has important implications for cancer screening, early diagnosis, and disease prognosis. A role for germline variation has also been described in shaping the molecular landscape, immune response, microenvironment, and treatment response of individual tumors. However, there is a lack of consensus on the handling and analysis of germline information that extends beyond known or suspected cancer susceptibility in large-scale cancer genomics initiatives. As part of the Personalized OncoGenomics program in British Columbia, we performed whole-genome and transcriptome sequencing in paired tumor and normal tissues from advanced cancer patients to characterize the molecular tumor landscape and identify putative targets for therapy. Overall, our experience supports a multidisciplinary and integrative approach to germline data management. This includes a need for broader definitions and standardized recommendations regarding primary and secondary germline findings in precision oncology. Here, we propose a framework for identifying, evaluating, and returning germline variants of potential clinical significance that may have indications for health management beyond cancer risk reduction or prevention in patients and their families.

Purpose: Immune checkpoint inhibitors (ICI) have revolutionized the treatment of solid tumors with dramatic and durable responses seen across multiple tumor types. However, identifying patients who will respond to these drugs remains challenging, particularly in the context of advanced and previously treated cancers. Experimental Design: We characterized fresh tumor biopsies from a heterogeneous pan-cancer cohort of 98 patients with metastatic predominantly pretreated disease through the Personalized OncoGenomics program at BC Cancer (Vancouver, Canada) using whole genome and transcriptome analysis (WGTA). Baseline characteristics and follow-up data were collected retrospectively. Results: We found that tumor mutation burden, independent of mismatch repair status, was the most predictive marker of time to progression (P = 0.007), but immune-related CD8+ T-cell and M1-M2 macrophage ratio scores were more predictive for overall survival (OS; P = 0.0014 and 0.0012, respectively). While CD274 [programmed death-ligand 1 (PD-L1)] gene expression is comparable with protein levels detected by IHC, we did not observe a clinical benefit for patients with this marker. We demonstrate that a combination of markers based on WGTA provides the best stratification of patients (P = 0.00071, OS), and also present a case study of possible acquired resistance to pembrolizumab in a patient with non–small cell lung cancer. Conclusions: Interpreting the tumor-immune interface to predict ICI efficacy remains challenging. WGTA allows for identification of multiple biomarkers simultaneously that in combination may help to identify responders, particularly in the context of a heterogeneous population of advanced and previously treated cancers, thus precluding tumor type–specific testing.

Purpose Children with acute myeloid leukemia (AML) whose disease is refractory to standard induction chemotherapy therapy or who experience relapse after initial response have dismal outcomes. We sought to comprehensively profile pediatric AML microRNA (miRNA) samples to identify dysregulated genes and assess the utility of miRNAs for improved outcome prediction. Patients and Methods To identify miRNA biomarkers that are associated with treatment failure, we performed a comprehensive sequence-based characterization of the pediatric AML miRNA landscape. miRNA sequencing was performed on 1,362 samples—1,303 primary, 22 refractory, and 37 relapse samples. One hundred sixty-four matched samples—127 primary and 37 relapse samples—were analyzed by using RNA sequencing. Results By using penalized lasso Cox proportional hazards regression, we identified 36 miRNAs the expression levels at diagnosis of which were highly associated with event-free survival. Combined expression of the 36 miRNAs was used to create a novel miRNA-based risk classification scheme (AMLmiR36). This new miRNA-based risk classifier identifies those patients who are at high risk (hazard ratio, 2.830; P ≤ .001) or low risk (hazard ratio, 0.323; P ≤ .001) of experiencing treatment failure, independent of conventional karyotype or mutation status. The performance of AMLmiR36 was independently assessed by using 878 patients from two different clinical trials (AAML0531 and AAML1031). Our analysis also revealed that miR-106a-363 was abundantly expressed in relapse and refractory samples, and several candidate targets of miR-106a-5p were involved in oxidative phosphorylation, a process that is suppressed in treatment-resistant leukemic cells. Conclusion To assess the utility of miRNAs for outcome prediction in patients with pediatric AML, we designed and validated a miRNA-based risk classification scheme. We also hypothesized that the abundant expression of miR-106a could increase treatment resistance via modulation of genes that are involved in oxidative phosphorylation.

Background NRG1 fusion-positive lung cancers have emerged as potentially actionable events in lung cancer, but clinical support is currently limited and no evidence of efficacy of this approach in cancers beyond lung has been shown. Patients and methods Here, we describe two patients with advanced cancers refractory to standard therapies. Patient 1 had lung adenocarcinoma and patient 2 cholangiocarcinoma. Whole-genome and transcriptome sequencing were carried out for these cases with select findings validated by fluorescence in situ hybridization. Results Both tumors were found to be positive for NRG1 gene fusions. In patient 1, an SDC4–NRG1 gene fusion was detected, similar gene fusions having been described in lung cancers previously. In patient 2, a novel ATP1B1–NRG1 gene fusion was detected. Cholangiocarcinoma is not a disease type in which NRG1 fusions had been described previously. Integrative genome analysis was used to assess the potential functional significance of the detected genomic events including the gene fusions, prioritizing therapeutic strategies targeting the HER-family of growth factor receptors. Both patients were treated with the pan HER-family kinase inhibitor afatinib and both displayed significant and durable response to treatment. Upon progression sites of disease were sequenced. The lack of obvious genomic events to describe the disease progression indicated that broad transcriptomic or epigenetic mechanisms could be attributed to the lack of prolonged response to afatinib. Conclusion These observations lend further support to the use of pan HER-tyrosine kinase inhibitors for the treatment of NRG1 fusion-positive in both cancers of lung and hepatocellular origin and indicate more broadly that cancers found to be NRG1 fusion-positive may benefit from such a clinical approach regardless of their site of origin. Clinical trial information Personalized Oncogenomics (POG) Program of British Columbia: Utilization of Genomic Analysis to Better Understand Tumour Heterogeneity and Evolution (NCT02155621).

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers worldwide and represents a heterogeneous group of tumors, the majority of which are treated with a combination of surgery, radiation, and chemotherapy. Fluoropyrimidine (5-FU) and its oral prodrug, capecitabine, are commonly prescribed treatments for several solid tumor types including HNSCC. 5-FU-associated toxicity is observed in ∼30% of treated patients and is largely caused by germline polymorphisms in DPYD, which encodes dihydropyrimidine dehydrogenase, a key enzyme of 5-FU catabolism and deactivation. Although the association of germline DPYD alterations with toxicity is well-described, the potential contribution of somatic DPYD alterations to 5-FU sensitivity has not been explored. In a patient with metastatic HNSCC, in-depth genomic and transcriptomic integrative analysis on a biopsy from a metastatic neck lesion revealed alterations in genes that are associated with 5-FU uptake and metabolism. These included a novel somatic structural variant resulting in a partial deletion affecting DPYD, a variant of unknown significance affecting SLC29A1, and homozygous deletion of MTAP. There was no evidence of deleterious germline polymorphisms that have been associated with 5-FU toxicity, indicating a potential vulnerability of the tumor to 5-FU therapy. The discovery of the novel DPYD variant led to the initiation of 5-FU treatment that resulted in a rapid response lasting 17 wk, with subsequent relapse due to unknown resistance mechanisms. This suggests that somatic alterations present in this tumor may serve as markers for tumor sensitivity to 5-FU, aiding in the selection of personalized treatment strategies.

Advanced and metastatic tumors with complex treatment histories drive cancer mortality. Here we describe the POG570 cohort, a comprehensive whole-genome, transcriptome and clinical dataset, amenable for exploration of the impacts of therapies on genomic landscapes. Previous exposure to DNA-damaging chemotherapies and mutations affecting DNA repair genes, including POLQ and genes encoding Polζ, were associated with genome-wide, therapy-induced mutagenesis. Exposure to platinum therapies coincided with signatures SBS31 and DSB5 and, when combined with DNA synthesis inhibitors, signature SBS17b. Alterations in ESR1, EGFR, CTNNB1, FGFR1, VEGFA and DPYD were consistent with drug resistance and sensitivity. Recurrent noncoding events were found in regulatory region hotspots of genes including TERT, PLEKHS1, AP2A1 and ADGRG6. Mutation burden and immune signatures corresponded with overall survival and response to immunotherapy. Our data offer a rich resource for investigation of advanced cancers and interpretation of whole-genome and transcriptome sequencing in the context of a cancer clinic.

Chordomas are neoplasms derived from notochord cells that typically form in the spine or skull base, and affect both adults and children. Poorly differentiated chordomas, associated with particularly poor outcomes, occur predominantly in children and are characterized by expression of the transcription factor brachyury and loss of INI1/SMARCB1. The use of immune checkpoint inhibitors in pediatric cancer is of growing interest, with reported anti-tumour activity in pediatric Hodgkin lymphoma and gliomas with mismatch repair deficiency. However, responses to immune checkpoint inhibitors are infrequent and unpredictable in pediatric solid tumours, and the molecular markers that can distinguish the seemingly indiscriminate response remain to be defined. Understanding which pediatric patient populations may benefit from immune checkpoint inhibitor therapies is essential. Here we describe the molecular profiles of two pediatric poorly differentiated chordomas using whole-genome, transcriptome and whole-genome bisulfite sequencing as part of the Personalized Oncogenomics program at BC Cancer (NCT02155621) that studies the impact of embedding comprehensive genomic profiling into the clinical care of advanced cancer patients. Genomic profiling and multiplex IHC revealed a high level of CD8+ T cells in both chordoma samples, despite low mutation burden. DNA methylation-based clustering revealed similarities with SMARCB1-deficient rhabdoid tumour subtypes that are have been characterized by increased levels of immune cell infiltration. A dominant tumour-associated T cell receptor clone was identified in one patient sample, which was demonstrated to have affinity for reconstituted brachyury-MHC complexes, indicating a potential anti-tumour immune response directed against brachyury-derived antigens. As these collective observations pointed to a potential benefit of immune targeted therapy, the patient was treated with nivolumab and subsequently achieved a partial radiographic response by RANO criteria. These observations provide support for the benefit of immune checkpoint inhibitors in poorly differentiated chordomas with high levels of infiltrating CD8+ T cells. Citation Format: Laura Williamson, Craig Rive, Daniela Di Francesco, Emma Titmuss, Elizabeth Chun, Scott Brown, Katy Milne, Erin Pleasance, Anna F. Lee, Stephen Yip, David Dix, Daniel Renouf, Robert Holt, Brad H. Nelson, Martin Hirst, Steven Jones, Shahrad Rassekh, Rebecca Deyell, Janessa Laskin, Macro A. Marra. Response to nivolumab in a pediatric chordoma with overexpression of brachyury [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 630.

Dramatic and durable responses to immune checkpoint inhibitors (ICIs) have been observed across multiple tumor types, but identifying the patients most likely to respond to these drugs remains challenging, particularly in the context of metastatic and pre-treated disease. Recent clinically approved biomarkers for patient selection are tumor agnostic, but currently all approved markers are evaluated independently. Through the Personalized Onco Genomics (POG) program at BC Cancer, we aimed to study the impact of evaluating multiple biomarkers in a tumor agnostic cohort. We performed whole genome and transcriptome analysis (WGTA) on fresh tumor biopsies from a heterogeneous pan-cancer cohort of 82 patients with advanced metastatic disease subsequently treated with ICIs. Established biomarkers, including tumor mutation burden (TMB) and CD8+ T cell scores, were able to distinguish responders in our advanced and pre-treated cohort. Additionally, we discovered that combining multiple biomarkers provided the best stratification of patients, suggesting a multifaceted approach, such as WGTA, may be suitable for more accurate identification of patients that may benefit from ICIs. As such, we have initiated a Phase II clinical trial, CAPTIV-8 (NCT04273061), which is distinctive in its use of WGTA to evaluate multiple markers including TMB, CD8+ T cell scores, an M1-M2 macrophage score and viral integration to select patients most likely to respond to atezolizumab. Clinical and genomic data prospectively collected from two hundred patients will be evaluated to test the efficacy of combining these biomarkers and identify additional biomarkers of response which can be used to guide treatment with ICIs. Citation Format: Emma Titmuss, Alexandra Pender, Erin Pleasance, Scott Brown, Cameron J. Grisdale, James Topham, Yaoqing Shen, Melika Bonakdar, Gregory A. Taylor, Laura Williamson, Karen Mungall, Eric Chuah, Andrew J. Mungall, Richard A. Moore, Jean-Michel Lavoie, Stephen Yip, Howard Lim, Daniel J. Renouf, Sophie Sun, Steven J. Jones, Robert Holt, Marco A. Marra, Janessa Laskin. CAPTIV-8: A prospective trial of atezolizumab using a multivariate model incorporating whole genome and transcriptome analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1647.

Sequencing technology is increasingly essential in clinical cancer management. The majority of clinical cancer sequencing has focused on panel approaches, but recent trials have begun to report the use of transcriptome expression profiling to match patients to therapy. The Personalized OncoGenomics (POG) program at BC Cancer has sequenced over 500 patient tumors, integrating both whole genome and transcriptome data to inform treatment options for patients with advanced or metastatic disease. Here we present 570 patients who were sequenced from 2012 to 2017 and reviewed at the POG multidisciplinary molecular tumor board. Genome and transcriptome information identified clinically actionable targets in 83% (475/570) of sequenced cases, with 37% (209/570) receiving POG-informed therapy. Overall, 248 whole genome and transcriptome sequencing analysis (WGTA)-informed treatments were administered, with some patients receiving multiple treatment courses. Of the treated cases, 46% (114/248) were reported to have physician-assessed clinical benefit. Clinical benefit was assessed as per standard of care rather than strict timing as per RECIST criteria. Mutation, copy number, structural variant, expression, and genome signature data were all used individually or in combination to inform treatments. Treatments based in whole or in part from RNA expression data were the largest subgroup (66.9%, 166/248), and patients in this group had similar proportion of clinical benefit compared to those receiving treatments informed by DNA-based data. Importantly, the use of RNA data resulted in 14.5% (36/248) additional patients receiving WGTA-informed treatments with clinical benefit. Patients were directed to clinical trials, treated with therapeutics in off-label indications, or positioned to genomically-informed standard of care options. For a subset of 42 cases where the planned next line of therapy was documented prior to WGTA analysis, 76.2% (32/42) of genomically-informed standard therapies were different from those which would otherwise have been considered the next line of therapy by the treating clinician, or aided in a decision between multiple different therapy options under consideration. These results emphasize the importance of multiple data types, including expression information, to personalize treatment. We also observe that, in addition to positioning for trials or identifying cases for off-label treatment, choice of standard of care therapies is an important use of genomic data. Overall, our data supports the integration of whole genome and RNA sequencing data in the clinic, with implications both for cancer research and treatment, and ultimately the potential to improve cancer outcomes. Citation Format: Alexandra K. Bohm, Erin Pleasance, Emma Tittmus, Kathleen Wee, Gregory Taylor, Melika Bonakdar, Yaoqing Shen, Laura Williamson, Veronika Csizmok, Martin Jones, Jessica Nelson, Balvir Deol, Caralyn Reisle, Karen Mungall, Eric Chuah, Andrew Mungall, Richard Moore, Sophie Sun, Howard Lim, Daniel Renouf, Steven Jones, Marco Marra, Janessa Laskin. Personalized therapy choice integrating genome and expression data in advanced cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 98.

The use of comprehensive personal genomic data to guide cancer treatment decisions has demonstrated success in recent years. However, its application to pediatric cancer remains challenging. Most pediatric cancer genomes have relatively few somatic aberrations and the recognized oncogenic drivers are often not targetable. Here we describe a whole genome and transcriptome analysis approach to elucidate the impact of currently un-targetable disease drivers on pathways and regulatory networks within cancer cells, in an effort to identify aberrations that can be targeted therapeutically. In the pediatric personalized oncogenomics (PedsPOG) project, we have analyzed 81 pediatric and young adult cases representing diverse types of relapsed, refractory or very poor prognosis cancers (17 primary central nervous system (CNS), 5 hematopoietic and lymphoid malignancies, and 59 from a variety of non-CNS solid cancers). Patients' ages ranged from 0.4-20.7 years at enrollment, with a median of 11.5 years. For each patient, genomic sequencing data from tumour and normal samples were analysed to detect germline and somatic variants including simple mutations to more complex alterations such as gene fusions, mutation burden and mutation signatures. Tumour transcriptome data was analyzed to identify aberrant gene expression and calculate immune-related signatures such as presence and composition of T cells in the tumour sample. Combined interpretation of germline and somatic variants was used to understand the underlying tumour biology and provide rationale for treatment options. Using the integrated analysis of genomic and transcriptomic data, actionable targets were identified in 80 out of 81 patients (98%), while therapeutic targets would have been identified in only 32-50% of the patients if individual genomic variants were used separately (such as mutation, fusion, and copy number changes). RNA expression data appears to be highly informative, from which targets were detected in 90% of the patients, albeit at lower levels of evidence. In particular, prediction of outlier T-cell presence based on expression data was identified as a potential biomarker which led to favorable response to immune checkpoint inhibition. Twenty-four cases received PedsPOG-informed therapy and disease response was evaluated by RECIST or RANO criteria. Complete response was observed in four patients, and thirteen patients demonstrated partial response or stable disease. In conclusion, the use of whole genome sequencing and transcriptome sequencing has yielded novel findings and therapeutic options in children and adolescents with poor prognosis cancer. Citation Format: Yaoqing Shen, Melika Bonakdar, Laura Williamson, Erin Pleasance, Karen Mungall, Richard A. Moore, Andrew J. Mungall, Stephen Yip, Anna F. Lee, Christopher Dunham, Janessa Laskin, Marco M. Marra, Steven J. Jones, Shahrad R. Rassekh, Rebecca J. Deyell. Application of integrated analysis of whole genome sequencing and RNA sequencing to personalized therapy decision making in pediatric and young adult cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 260.

Personalised oncogenomics analysis revealed potential oncogene addiction of the AP-1 transcriptional complex in a chemo-refractory and MMR-deficient tumor from a patient with metastatic colon cancer. Based on this, treatment with the angiotensin receptor agonist irbesartan was initiated to target the renin–angiotensin system upstream of the AP-1 complex, leading to a profound and durable response., Background A patient suffering from metastatic colorectal cancer, treatment-related toxicity and resistance to standard chemotherapy and radiation was assessed as part of a personalized oncogenomics initiative to derive potential alternative therapeutic strategies. Patients and methods Whole-genome and transcriptome sequencing was used to interrogate a metastatic tumor refractory to standard treatments of a patient with mismatch repair-deficient metastatic colorectal cancer. Results Integrative genomic analysis indicated overexpression of the AP-1 transcriptional complex suggesting experimental therapeutic rationales, including blockade of the renin–angiotensin system. This led to the repurposing of the angiotensin II receptor antagonist, irbesartan, as an anticancer therapy, resulting in the patient experiencing a dramatic and durable response. Conclusions This case highlights the utility of comprehensive integrative genomic profiling and bioinformatics analysis to provide hypothetical rationales for personalized treatment options.

472 Background: There is emerging evidence about the predictive role of homologous recombination deficiency (HRD) in multiple cancers. The clinical utility of HRD is less well defined in gastrointestinal (GI) malignancies. Methods: We reviewed the whole genome (WGS) and transcriptomic (RNA-Seq) data of patients with advanced GI cancers between 2012-2018 in the Personalized Oncogenomics trial (NCT02155621). Scores were calculated as the sum of loss of heterozygosity, telomeric allelic imbalance, and large-scale state transitions scores. HRD was defined as a score ≥34. Mutational analysis was performed to determine the presence of mutational signature 3, which is usually strongly associated with BRCA status. Retrospective chart review was conducted to extract treatment and survival outcomes. Overall survival (OS) from initiation of first-line systemic therapy and time to progression on platinum therapy (TTPp) were calculated. Linear and multivariable regression analyses were conducted. Results: Of 154 patients with GI primaries, 56% were male and 105 (68%) were exposed to a platinum agent in the metastatic setting. Primary sites included upper GI (N=20, 9%), pancreas (N=35, 16%), colorectal (N=74, 33%), and other GI primary (N=25, 11%). Ten patients (6%) had a BRCA1/2 mutation, 20 (13%) had a high HRD score, and 11 (7%) had a high signature 3 score (>0.05). Six patients had both high HRD and high signature 3 scores (Table). On linear regression, high HRD scores and mutational signature 3 were independently associated with longer TTPp (β=4.17, 95% CI 0.15-8.19, p=0.04; β=8.03, 95% CI 2.87-13.18, p

Background Immune checkpoint inhibitors (CPI) have revolutionised the treatment of solid tumours with durable responses in cancers with previously limited treatment options. Despite significant improvements in overall survival for some patients(pt), identifying biomarkers to select a population most likely to benefit from CPIs remains challenging. Methods We characterized fresh tumour biopsies from 82 pts with metastatic cancer through the Personalised OncoGenomics (POG) program at BC Cancer using whole genome (80X tumour, 40X normal) and transcriptome analysis (WGTA). Subsequently pts were treated with a CPI as part of their standard cancer care. Baseline characteristics and follow up data were collected retrospectively. Durable clinical benefit (DCB) was defined as > 6 months(m) without disease progression and overall survival (OS) from date of first CPI treatment to death. Results The 82 pts (59% female) biopsied comprised a heterogeneous cohort: non-small cell lung cancer (30%), breast (17%) and colorectal cancer (13%) were most common, and most patients (45%) had received 1-2 prior treatments. 17 patients (21%) had a DCB and the median follow-up from first dose CPI was 9.2m. Higher tumour mutation burden (>10mut/Mb exome) was predictive of a longer median time to progression/death (TTPD) (5.9 vs 2.6m, p = 0.0055, HR = 0.44) and OS (14.6 vs 7.9m, p = 0.039, HR = 0.52). A higher predicted CD8+ T cell score (CIBERSORT) also predicted for a prolonged median TTPD (3.4 vs 2.4 m, p = 0.0094, HR = 0.51) and OS (12.9 vs 5.3m, p = 0.0014, HR = 0.42). In contrast, patients with PD-L1 expression > 80th percentile did not have a significantly different TTPD or OS. In addition to characterizing individual biomarkers, we note that patients with combinations of markers, particularly high TMB and CD8+ T cell scores, have a further improvement in median TTPD (5.9 vs 2.4m, p = 0.013) and OS (14.5 vs 5.4m, p = 0.014). Conclusions The complexity of interpreting the tumour-immune interface to predict CPI efficacy remains challenging, but WGTA allows for identification of combination biomarkers that may help to identify responders. The presence of two or more biomarkers predicted for CPI response in this patient cohort and may more successfully identify these patients in prospective studies. Legal entity responsible for the study The authors. Funding BC Cancer Foundation. Disclosure J. Lavoie: Research grant / Funding (self): University of British Columbia. S. Yip: Advisory / Consultancy: Pfizer; Advisory / Consultancy: Roche; Advisory / Consultancy: Bayer. D. Renouf: Honoraria (self): Celgene; Honoraria (self): Servier; Honoraria (self): Taiho; Honoraria (self): Ipsen; Honoraria (self), Research grant / Funding (institution): Bayer. J.J. Laskin: Honoraria (self), Research grant / Funding (institution): Roche Canada; Honoraria (self): BI Canada; Honoraria (self), Research grant / Funding (institution): AstraZeneca Canada; Research grant / Funding (institution): Pfizer Canada. All other authors have declared no conflicts of interest.

Metastatic adenoid cystic carcinomas (ACCs) can cause significant morbidity and mortality. Because of their slow growth and relative rarity, there is limited evidence for systemic therapy regimens. Recently, molecular profiling studies have begun to reveal the genetic landscape of these poorly understood cancers, and new treatment possibilities are beginning to emerge. The objective is to use whole-genome and transcriptome sequencing and analysis to better understand the genetic alterations underlying the pathology of metastatic and rare ACCs and determine potentially actionable therapeutic targets. We report five cases of metastatic ACC, not originating in the salivary glands, in patients enrolled in the Personalized Oncogenomics (POG) Program at the BC Cancer Agency. Genomic workup included whole-genome and transcriptome sequencing, detailed analysis of tumor alterations, and integration with existing knowledge of drug–target combinations to identify potential therapeutic targets. Analysis reveals low mutational burden in these five ACC cases, and mutation signatures that are commonly observed in multiple cancer types. Notably, the only recurrent structural aberration identified was the well-described MYB-NFIB fusion that was present in four of five cases, and one case exhibited a closely related MYBL1-NFIB fusion. Recurrent mutations were also identified in BAP1 and BCOR, with additional mutations in individual samples affecting NOTCH1 and the epigenetic regulators ARID2, SMARCA2, and SMARCB1. Copy changes were rare, and they included amplification of MYC and homozygous loss of CDKN2A in individual samples. Genomic analysis revealed therapeutic targets in all five cases and served to inform a therapeutic choice in three of the cases to date.

Purpose: Recent studies have identified mutation signatures of homologous recombination deficiency (HRD) in over 20% of breast cancers, as well as pancreatic, ovarian, and gastric cancers. There is an urgent need to understand the clinical implications of HRD signatures. Whereas BRCA1/2 mutations confer sensitivity to platinum-based chemotherapies, it is not yet clear whether mutation signatures can independently predict platinum response.Experimental Design: In this observational study, we sequenced tumor whole genomes (100× depth) and matched normals (60×) of 93 advanced-stage breast cancers (33 platinum-treated). We computed a published metric called HRDetect, independently trained to predict BRCA1/2 status, and assessed its capacity to predict outcomes on platinum-based chemotherapies. Clinical endpoints were overall survival (OS), total duration on platinum-based therapy (TDT), and radiographic evidence of clinical improvement (CI).Results: HRDetect predicted BRCA1/2 status with an area under the curve (AUC) of 0.94 and optimal threshold of 0.7. Elevated HRDetect was also significantly associated with CI on platinum-based therapy (AUC = 0.89; P = 0.006) with the same optimal threshold, even after adjusting for BRCA1/2 mutation status and treatment timing. HRDetect scores over 0.7 were associated with a 3-month extended median TDT (P = 0.0003) and 1.3-year extended median OS (P = 0.04).Conclusions: Our findings not only independently validate HRDetect, but also provide the first evidence of its association with platinum response in advanced breast cancer. We demonstrate that HRD mutation signatures may offer clinically relevant information independently of BRCA1/2 mutation status and hope this work will guide the development of clinical trials. Clin Cancer Res; 23(24); 7521–30. ©2017 AACR.

Extraordinary advancements in sequencing technology have made what was once a decade-long multi-institutional endeavor into a methodology with the potential for practical use in a clinical setting. We therefore set out to examine the clinical value of next-generation sequencing by enrolling patients with incurable or ambiguous tumors into the Personalized OncoGenomics initiative at the British Columbia Cancer Agency whereby whole genome and transcriptome analyses of tumor/normal tissue pairs are completed with the ultimate goal of directing therapeutics. First, we established that the sequencing, analysis, and communication with oncologists could be completed in less than 5 weeks. Second, we found that cancer diagnostics is an area that can greatly benefit from the comprehensiveness of a whole genome analysis. Here, we present a scenario in which a metastasized sphenoid mass, which was initially thought of as an undifferentiated squamous cell carcinoma, was rediagnosed as an SMARCB1-negative rhabdoid tumor based on the newly acquired finding of homozygous SMARCB1 deletion. The new diagnosis led to a change in chemotherapy and a complete nodal response in the patient. This study also provides additional insight into the mutational landscape of an adult SMARCB1-negative tumor that has not been explored at a whole genome and transcriptome level.

Variability in the immunogenic landscape of metastatic cancer lesions has revealed insight into detection of potential immunotherapy-responsive patients, though underlying mechanisms driving such variation are not fully understood. Endogenous retrovirus (ERV)-containing transcripts have recently emerged as a potential source of tumor-associated antigen that are orthogonal to somatic mutation-derived neoantigens. To characterize the intersection between ERV levels and predicted immunogenicity in metastatic cancer, we comprehensively profiled the transcript abundance of 702,533 ERV loci in 199 metastatic tumors from breast, colorectal, and pancreatic cancer patients. In all three cancer types, overall ERV transcript load was associated with upregulation of genes involved in innate antiviral response pathways as well as genes involved in both adaptive and innate immune signaling. In colorectal and pancreatic tumors, samples with concomitant increases in ERV load and antiviral response gene expression, termed viral mimicry tumors, showed high expression of the DNA demethylation gene TET2, a gene previously described to promote transcription of ERV-containing transcripts. Collectively, these data are compatible with the notion that an increased level of ERV-containing transcripts may account for increased immunogenicity in a subset of metastatic tumors and support the relationship between DNA demethylation and ERV load in colorectal and pancreatic tumors. Citation Format: James T. Topham, Emma Titmuss, Erin Pleasance, Laura M. Williamson, Joanna M. Karasinska, Luka Culibrk, Michael K.C. Lee, Steve E. Kalloger, Shehara Mendis, Richard A. Moore, Andrew J. Mungall, Janessa Laskin, Jonathan M. Loree, Dixie L. Mager, Marco A. Marra, Steven J.M. Jones, David F. Schaeffer, Daniel J. Renouf. Endogenous retrovirus transcript levels are associated with immunogenic signatures in multiple metastatic cancer types [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B56.

We describe the case of an 11-month-old girl with a rare cerebellar glioblastoma driven by a NACC2-NTRK2 (Nucleus Accumbens Associated Protein 2-Neurotrophic Receptor Tyrosine Kinase 2) fusion. Initial workup of our case demonstrated homozygous CDKN2A deletion, but immunohistochemistry for other driver mutations, including IDH1 R132H, BRAF V600E, and H3F3A K27M were negative, and ATRX was retained. Tissue was subsequently submitted for personalized oncogenomic analysis, including whole genome and whole transcriptome sequencing, which demonstrated an activating NTRK2 fusion, as well as high PD-L1 expression, which was subsequently confirmed by immunohistochemistry. Furthermore, H3 and IDH demonstrated wildtype status. These findings suggested the possibility of treatment with either NTRK- or immune checkpoint- inhibitors through active clinical trials. Ultimately, the family pursued standard treatment that involved Head Start III chemotherapy and proton radiotherapy. Notably, at most recent follow upapproximately two years from initial diagnosis, the patient is in disease remission and thriving, suggesting favorable biology despite histologic malignancy. This case illustrates the value of personalized oncogenomics, as the molecular profiling revealed two actionable changes that would not have been apparent through routine diagnostics. NTRK fusions are known oncogenic drivers in a range of cancer types, but this is the first report of a NACC2-NTRK2 fusion in a glioblastoma.LEARNING OBJECTIVESThis presentation will enable the learner to:1.Explore the current molecular landscape of pediatric high grade gliomas2.Recognize the value of personalized oncogenomic analysis, particularly in rare and/or aggressive tumors3.Discuss the current status of NTRK inhibitor clinical trials